Investigation of wind characteristics and assessment of wind energy potential for Waterloo region,Canada

Wind energy becomes more and more attractive as one of the clean renewable energy resources. Knowledge of the wind characteristics is of great importance in the exploitation of wind energy resources for a site. It is essential in designing or selecting a wind energy conversion system for any application. This study examines the wind characteristics for the Waterloo region in Canada based on a data source measured at an elevation 10 m above the ground level over a 5-year period (1999–2003) with the emphasis on the suitability for wind energy technology applications. Characteristics such as annual, seasonal, monthly and diurnal wind speed variations and wind direction variations are examined. Wind speed data reveal that the windy months in Waterloo are from November to April, defined as the Cold Season in this study, with February being the windiest month. It is helpful that the high heating demand in the Cold Season coincides with the windy season. Analysis shows that the day time is the windy time, with 2 p.m. in the afternoon being the windiest moment. Moreover, a model derived from the maximum entropy principle (MEP) is applied to determine the diurnal, monthly, seasonal and yearly wind speed frequency distributions, and the corresponding Lagrangian parameters are determined. Based on these wind speed distributions, this study quantifies the available wind energy potential to provide practical information for the application of wind energy in this area. The yearly average wind power density is 105 W/m². The day and night time wind power density in the Cold Season is 180 and 111 W/m², respectively.     

Wind power utilization for water pumping using small wind turbines in Saudi Arabia: A techno-economical review

An attempt has been made, may be first time in Saudi Arabia, to utilize power of the wind for pumping the water for remotely located inhabitants not connected with national power grid. Small turbines of 1–10 kW have been chosen in conjunction with Goulds 45 J model water pumps to produce energy from wind and pump water using the produced energy at Arar, Rawdat Ben Habbas and Juaymah localities in Saudi Arabia. Wind speed measurements made at different heights using 40 m tall towers have been utilized in the present work. Higher wind speeds were noticed during summer time compared to winter time at all the locations. Both energy yield and cost of energy point of view, 2.5 kW wind turbine from Proven was found to be most suitable for wind power generation at all sites. It is shown that annual total water pumping capacity of 30,000 m³ is possible from a depth of total dynamic head of 50 m when using 2.5 kW Proven wind turbine with hub heights 15–40 m at all three sites with cost of water pumping as low as 1.28 US¢/m³.     

Feasibility study of hydrogen production from wind power in the region of Ghardaia

A feasibility study on hydrogen production from wind power on the site of Ghardaia is carried out. This study is based on the estimation of the hydrogen rate produced by a 5 kW electrolyser fed by the electricity provided by a 10 kW wind turbine.Wind speed data were used to study the monthly variation of the wind power delivered and its variation according to the height of the wind turbine tower.The obtained results show that it is possible to improve the system output by increasing the height of the wind turbine tower. Indeed, it has been obtained 3200 Nm³ of hydrogen production for a 30 m wind turbine height and 4200 Nm³ at 60 m.In addition, it has been noticed that hydrogen production varies strongly with the months of the year. Thus, the production has reached a maximum of 395 Nm³ in May and a minimum of 187 Nm³ during November and October.     

6 years of wind data for Marsabit,Kenya average over 14 m/s at 100 m hub height; An analysis of the wind energy potential

The wind energy potential for generation of electricity and for domestic water pumping has been investigated for Marsabit, Kenya. Marsabit (37° 58′N, 2° 19′E) lies in Eastern province approximately 560 km from Nairobi. Wind data from the Kenya Meteorological department for the period 2001–2006 has been used to study the Diurnal, monthly and inter-annual variability using empirical methods including the Power law and Weibull statistics. Average wind speeds greater than11 m/s at a height of 10 m are prevalent in this area. The available power density at a height of 100 m is between 1776 W/m² and 2202 W/m² which is in the wind class range of 7 and 8. The maximum extractable power density at 100 m varied between 1417 W/m² and 1757 W/m². Values of Weibull parameters k (dimensionless) and c (m/s) ranged between 2.5–3.05 and 11.86–12.97 respectively. Wind Rose analysis revealed no marked variation in wind direction and frequency throughout the year (mean direction between 150 and 160 degrees with highest standard deviation of 33.5 degrees). From the analysis, the site was found suitable for grid connected power generation and also for other stand-alone generators that can be used for water pumping and battery charging.     

Monthly and seasonal assessment of wind energy characteristics at four monitored locations in Liguria region (Italy)

The aim of this paper is to investigate the monthly and seasonal variation of the wind characteristics in term of wind energy potential using the wind speed data collected between 2002 and 2008 for four meteorological stations in Liguria region, in Northwest of Italy, namely Capo Vado, Casoni, Fontana Fresca and Monte Settepani. The results show that Capo Vado is the best site with a monthly mean wind speed between 2.80 and 9.98 m/s at a height of 10 m and a monthly wind power density between 90.71 and 1177.97 W/m², while the highest energy produced may be reached in December with a value of 3800 MWh. This study may provide information for developing wind energy sites and planning economical wind turbines capacity for the electricity production in Liguria region, as well as an example of how, deepening the analysis at monthly and seasonal scale, the characteristics of the sites might fall in quite different classes of power density.     

Wind energy resources in the Ionian Sea

The wind speed and direction as well as the availability, the duration and the diurnal variation of two offshore sites, Zakinthos and Pylos (BZK and BPY) in the Ionian Sea were assessed. For an analysis period of two years, the mean wind speed at 10 m was determined as 5.7 ± 0.1 m s^?1 and 5.8 ± 0.1 m s^?1 for the BZK and BPY sites, respectively. The wind speed variations over the hours of the day were quite small. The monthly variation in the average wind speeds was between 4.3 (May) and 7.5 m s^?1 (December) for the BZK site and 4.4 (August) and 7.3 m s^?1 (December) for the BPY site. Moreover, QuikSCAT satellite mean values for the grids of the two buoy regions were systematically overestimated in comparison to the buoy data with differences in the range from 8 to 13%. Statistical analysis revealed the high QuikSCAT data uncertainty for wind speeds less than 5 m s^?1 as the major factor of the observed mean value differences. The mean wind power densities were calculated with the buoy wind speed measurements and were found more than 250 W m^?2 at 10 m, suggesting the suitability of the sites for offshore wind energy applications. Capacity factors of up to 48% for energy production were calculated with the existing offshore turbines technology at a hub height of 100 m. Furthermore, the energy yield for different wind turbines and a service life of 20 years were determined from 6.5 to 8.7 and the energy pay-back periods from 2.8 to 2.1 years, respectively. The maximum avoided greenhouse emissions were 140 kt CO₂-e for an offshore turbine generator of 5 MW and a period of 20 years.     

Wind forecasts for wind power generation using the Eta model

The goal of this article is to apply the regional atmospheric numerical weather prediction Eta model and describe its performance in validation of the wind forecasts for wind power plants. Wind power generation depends on wind speed. Wind speed is converted into power through characteristic curve of a wind turbine. The forecasting of wind speed and wind power has the same principle.Two sets of Eta model forecasts are made: one with a coarse resolution of 22 km, and another with a nested grid of 3.5 km, centered on the Nasudden power plants, (18.22°E, 57.07°N; 3 m) at island Gotland, Sweden. The coarse resolution forecasts were used for the boundary conditions of the nested runs. Verification is made for the nested grid model, for summers of 1996–1999, with a total number of 19 536 pairs of forecast and observed winds. The Eta model is compared against the wind observed at the nearest surface station and against the wind turbine tower 10 m wind. As a separate effort, the Eta model wind is compared against the wind from tower observations at a number of levels (38, 54, 75 and 96 m).Four common measures of accuracy relative to observations - mean difference (bias), mean absolute difference, root mean square difference and correlation coefficient are evaluated. In addition, scatter plots of the observed and predicted pairs at 10 and 96 m are generated. Average overall results of the Eta model 10 m wind fits to tower observations are: mean difference (bias) of 0.48 m/s, mean absolute difference of 1.14 m/s, root mean square difference of 1.38 m/s, and the correlation coefficient of 0.79. Average values for the upper tower observation levels are the mean difference (bias) of 0.40 m/s; mean absolute difference of 1.46 m/s; root mean square difference of 1.84 m/s and the correlation coefficient of 0.80.     

Wind energy in the Gulf of Tunis,Tunisia

This paper presents a study of wind resource in the Gulf of Tunis. During 2008, an experimental measurement of wind speed and wind direction at 20 m and 30 m, were conducted using a 10-min time step. The statistic treatment of results permitted us to evaluate the most characteristics of wind energy in the studied site. An extrapolation of wind speed is, also, carried out using the deduced power law exponent. The annual production of the wind turbine Enercon E82 is estimated at a height of 100 m above ground level. The obtained results can be used to perform wind park project and confirm that the Gulf of Tunis has promising wind energy potential.     

Wind energy as a potential generation source at Ras Benas,Egypt

Analysis of the wind characteristics in Ras Benas city located on the east coast of Red Sea in Egypt using measured data (wind, pressure and temperature) and Weibull function were made.Statistical analysis model to evaluate the wind energy potential was introduced. According to the power calculations done for the site, the annual mean wind density is 315 kW/m² at a height of 70 m above ground level. This station has a huge wind energy potential for electricity generation, especially during spring and summer seasons, comparing with some European countries.In addition, the monthly wind turbine efficiency parameter (η_monthly) has been calculated by using a commercial wind turbine 1 MW with 70 m hub height to help designers and users in evaluating the potentialities and choosing the suitable wind turbine for the considered site. The use of wind turbine with capacity greater than 1000 kW at this station was recommended.Ras Benas station was selected to install 30 MW-wind farm consists of 20 commercial wind turbines (Nordex S 77) with hub heights and Rotor diameter were 100 and 77 m, respectively. This site has annual wind speed more than 9.8 m/s at 100 m height and enough area to locate these turbines.The estimated energy production using WASP Program of these wind farm was 130 GWh/year. Furthermore, the production costs was found 1.3€ cent/kWh, which is a competition price at the wind energy world market.     

Technical review of wind energy potential as small-scale power generation sources in Penang Island Malaysia

This project presents an investigation and assessment of the wind energy potential in Penang Island, located about 15 km off the west (W) coast of Peninsular Malaysia. The wind data were statistically analyzed using Rayleigh distribution function. Based on the investigation, the results show that the measurement site falls under Class 1 of the International System Wind Classification. The climate in Penang Island is highly influenced by the northeast (NE) and southwest (SW) monsoon seasons. Besides that, most of the wind is the prevailing wind from the north (N) and SW directions. Meanwhile, the directions that contribute higher energy frequency are from NE and south-southwest (SSW). The mean annual wind power density (WPD) in this regime is estimated to be about 24.54 W m^?2. Furthermore, the mean annual wind energy density (WED) is also forecast to be 17.98 kWh m^?2 month^?1. The total annual WED is 216 kWh m^?2 year^?1. Thus, the results of this investigation indicate that the grid-network connected to the wind turbine-generator systems may not be a commercially viable proposal in Penang. Nevertheless, a small-scale wind turbine system is more suitable and sustainable in Penang Island.     

Sustainable energy options for Pakistan

With the advent of the year 2008, Pakistan faces a gap of 4500 MW between the demand and supply of electricity, registering a shortfall of 40%. The article provides an overview of the key dimensions of the crisis, i.e. growing gap between demand and supply, diminishing indigenous oil and gas reserves, rising energy cost and security concerns. It also explores hydropower, solar energy, biomass and wind power as sustainable energy options for the country. In has been found that the total estimated hydropower potential is more than 42 GW out of which only 6.5 GW has been tapped so far. In terms of available solar energy Pakistan is amongst the richest countries in the world, having an annual global irradiance value of 1900–2200 kWh/m². Despite that fact that the biomass plays an important role in the primary energy mix by contributing to 36% of the total supplies, it has not managed to break into the commercial energy market. Wind power, also been identified as a potential source of energy, is yet to take off.     

Wind power resource assessment for Rafha,Saudi Arabia

This paper, presents the analysis of wind speed data and available energy in Rafha area using wind machines of 600, 1000 and 1500 kW sizes from three manufacturers. The long-term annual mean values of wind speeds were found to vary between a minimum of 2.5 m/s in the year 2002 and a maximum of 4.9 m/s in 1990. The frequency distribution showed that wind remained silent for 7% of the time on an average during 24 years of data period and 35% between 0 and 3.5 m/s. Wind speed remained above 3.5 m/s for 65% of the time and only 20% of the times above 6.5 m/s. The annual wind energy production and plant capacity factors, obtained using different methods and wind machines of three sizes and from three manufacturers are also discussed and compared.     

Economic feasibility of large community feed-in tariff-eligible wind energy production in Nova Scotia

Nova Scotia, Canada's community feed-in tariff (COMFIT) scheme is the world's first feed-in tariff program specifically targeting locally-based renewable energy projects. This study investigated selected turbine capacities to optimize electricity production, based on actual wind profiles for three sites in Nova Scotia, Canada (i.e., Sydney, Caribou Point, and Greenwood). The turbine capacities evaluated are also eligible under the current COMFIT-large scheme in Nova Scotia, including 100 kW, 900 kW and 2.0 MW turbines. A capital budgeting model was developed and then used to evaluate investment decisions on wind power production. Wind duration curves suggest that Caribou Point had the highest average wind speeds but for shorter durations. By comparison, Sydney and Greenwood had lower average wind speeds but with longer durations. Electricity production cost was lowest for the 2.0 MW turbine in Caribou Point ($0.07 per kWh), and highest for the 100 kW turbine located in Greenwood ($0.49 per kWh). The most financially viable wind power project was the 2.0 MW turbine assumed to operate at 80 m hub height in Caribou Point, with NPV=$251,586, and BCR=1.51. Wind power production for the remaining two sites was generally not financially feasible for the turbine capacities considered. The impact of promoting local economic development from wind power projects was higher in a scenario under which wind turbines were clustered at a single site with the highest wind resources than generating a similar level of electricity by distributing the wind turbines across multiple locations.     

Assessing the economic wind power potential in Austria

In the European Union, electricity production from wind energy is projected to increase by approximately 16% until 2020. The Austrian energy plan aims at increasing the currently installed wind power capacity from approximately 1 GW to 3 GW until 2020 including an additional capacity of 700 MW until 2015. The aim of this analysis is to assess economically viable wind turbine sites under current feed-in tariffs considering constraints imposed by infrastructure, the natural environment and ecological preservation zones in Austria. We analyze whether the policy target of installing an additional wind power capacity of 700 MW until 2015 is attainable under current legislation and developed a GIS based decision system for wind turbine site selection.Results show that the current feed-in tariff of 9.7 ct kW h⁻¹ may trigger an additional installation of 3544 MW. The current feed-in tariff can therefore be considered too high as wind power deployment would exceed the target by far. Our results indicate that the targets may be attained more cost-effectively by applying a lower feed-in tariff of 9.1 ct kW h⁻¹. Thus, windfall profits at favorable sites and deadweight losses of policy intervention can be minimized while still guaranteeing the deployment of additional wind power capacities.     

Wind energy for rural areas of Algeria

This paper presents long-term analysis of wind speed data in terms of annual, seasonal and diurnal variations at Tindouf, which is situated on the south west region of Algeria. The wind speed data was collected over a period of 08 years between 1976 and 1984. The study showed that the long-term seasonal wind speeds were found to be relatively higher during September compared to other months. The diurnal change in long-term mean wind speed indicated that higher electricity could be produced during 09:00–18:00 h, which also coincides with higher electricity demand period. The annual wind energy production and capacity factor, obtained using wind speed frequency distribution and wind power curve of 1000 kW wind turbine and RETScreen software were found comparable with each other if unadjusted energy production values calculated by the software were used rather than the renewable energy delivered. Development of wind farm of 30 MW installed capacity at this site could result into avoidance of 23,252 tonnes/year of CO₂ equivalents GHG from entering into the local atmosphere thus creating a clean and healthy atmosphere for local inhabitants.     

Wind resource assessment of the Southern Appalachian Ridges in the Southeastern United States

The analysis of wind data collected throughout the Southern Appalachian Mountain region of the Southeastern US is presented. Data were collected at 50 m above ground level on nine ridge top sites between 2002 and 2005. Monthly average wind speeds, power densities, wind sheers, and turbulence intensities, along with monthly maximum gusts, are presented. Measured annual average wind speeds are compared to AWS TrueWind predictions. Diurnal variations in wind speed are also reported. Annual wind roses for each site are presented. Annual wind speeds range from 5.5 to 7.4 m/s with the highest annual average wind speeds found on ridges near the northern TN–NC border. A 20% winter and nighttime enhancement of the wind speed was observed. The prevailing wind is from the westerly directions. The estimated annual energy outputs from a small wind farm consisting of fifteen 1.5 MW GE turbines range from 50 to 75 MkWh, and estimated capacity factors range from 25% to 35%. This analysis suggests that ridges in the region are suitable for utility-scale wind development.     

Feasibility study of hybrid retrofits to an isolated off-grid diesel power plant

The green sources of energy are being encouraged to reduce the environmental pollution and combat the global warming of the planet. A target of 12% usage of wind energy only has been agreed by the UNO country members to achieve by 2020. So, the power of the wind is being used to generate electricity both as grid connected and isolated wind-diesel hybrid power plants. This paper performed a pre-feasibility of wind penetration into an existing diesel plant of a village in north eastern part of Saudi Arabia. For simulation purpose, wind speed data from a near by airport and the load data from the village have been used. The hybrid system design tool HOMER has been used to perform the feasibility study. In the present scenario, for wind speed less than 6.0 m/s the, the existing diesel power plant is the only feasible solution over the range of fuel prices used in the simulation. The wind diesel hybrid system becomes feasible at a wind speed of 6.0 m/s or more and a fuel price of 0.1 $/L or more. If the carbon tax is taken into consideration and subsidy is abolished then it is expected that the hybrid system become feasible. The maximum annual capacity shortage did not have any effect on the cost of energy which may be accounted for larger sizes of wind machines and diesel generators. It is recommended that the wind data must be collected at the village at three different heights using a wind mast of 40 m for a minimum of one complete year and then the hybrid system must be re-designed.     

Decentralized/stand-alone hybrid Wind–Diesel power systems to meet residential loads of hot coastal regions

In view of rising costs, pollution and fears of exhaustion of oil and coal, governments around the world are encouraging to seek energy from renewable/sustainable energy sources such as wind. The utilization of energy from wind (since the oil embargo of the 1970s) is being widely disseminated for displacement of fossil fuel produced energy and to reduce atmospheric degradation. A system that consists of a wind turbine and Diesel genset is called a Wind–Diesel power system.The literature indicates that the commercial/residential buildings in Saudi Arabia consume an estimated 10–40% of the total electric energy generated. In the present study, the hourly mean wind-speed data of the period 1986–1997 recorded at the solar radiation and meteorological station, Dhahran (26°32′N, 50°13′E in the Eastern Coastal Region of Saudi Arabia), has been analyzed to investigate the potential of utilizing hybrid (Wind–Diesel) energy conversion systems to meet the load requirements of a hundred typical two bedroom residential buildings (with annual electrical energy demand of 3512 MWh). The long term monthly average wind speeds for Dhahran range from 4.2 to 6.4 m/s. The hybrid systems considered in the present case study consist of different combinations/clusters of 150 kW commercial wind machines supplemented with battery storage and Diesel back-up. The deficit energy generated by the Diesel generator (for different battery capacities) and the number of operational hours of the Diesel system to meet a specific annual electrical energy demand of 3512 MWh have also been presented. The evaluation of the hybrid system shows that with seven 150 kW wind energy conversion system (WECS) and one day of battery storage, the Diesel back-up system has to provide 21.6% of the load demand. Furthermore, with three days of battery storage, the Diesel back-up system has to provide 17.5% of the load demand. However, in the absence of battery storage, about 37% of the load needs to be provided by the Diesel system. The study also places emphasis on the monthly average daily energy generation from different sizes (150 kW, 250 kW, 600 kW) of wind machines to identify the optimum wind machine size from the energy production point of view. It has been noted that for a given 6 MW wind farm size (for 50 m hub height), a cluster of forty 150 kW wind machines yields about 48% more energy as compared to a cluster of ten 600 kW wind machines.     

Modeling and forecasting the mean hourly wind speed time series using GMDH-based abductive networks

Wind speed forecasts are important for the operation and maintenance of wind farms and their profitable integration into power grids, as well as many important applications in shipping, aviation, and the environment. Modern machine learning techniques including neural networks have been used for this purpose, but it has proved hard to make significant improvements on the performance of the simple persistence model. As an alternative approach, we propose here the use of abductive networks, which offer the advantages of simplified and more automated model synthesis and transparent analytical input–output models. Various abductive models for predicting the mean hourly wind speed 1 h ahead have been developed using wind speed data at Dhahran, Saudi Arabia during the month of May over the years 1994–2005. The models were evaluated on the data for May 2006. Models described include a single generic model to forecast next-hour speed from the previous 24 hourly measurements and an hour index, which give an overall mean absolute error (MAE) of 0.85 m/s and a correlation coefficient of 0.83 between actual and predicted values. The model achieves an improvement of 8.2% reduction in MAE compared to hourly persistence. The above model was used iteratively to forecast the hourly wind speed 6 h and 24 h ahead at the end of a given day, with MAEs of 1.20 m/s and 1.42 m/s which are lower than forecasting errors based on day-to-day persistence by 14.6% and 13.7%. Relative improvements on persistence exceed those reported for several machine learning approaches reported in the literature.     

Wind shear coefficients,roughness length and energy yield over coastal locations in Southern Italy

In the present work a computation of wind shear coefficients (WSCs) based on 1-h measured wind data has been performed by three stations located over coastal sites in Southern Italy, i.e., Brindisi (BR), Portoscuso (PS) and Termini Imerese (TI). Wind observations have been collected through a 6-year period (January 1, 1997 to December 31, 2002) by wind mast recording at the same two sensor heights (i.e., 10 and 50 m AGL), thus enabling a proper wind profile analysis. WSC overall mean values were found to be 0.271 at BR, 0.232 at PS, and 0.150 at TI. In addition, a detailed analysis has been carried out to describe the WSC yearly, monthly and diurnal variation, as well as by wind direction. The characteristics of z₀ surface roughness length have been also investigated as an estimate for neutral stability conditions only, resulting in overall mean values of 0.526 m at BR, 0.287 m at PS, and 0.027 m at TI. The z₀ variation by year, month and hour of the day, as well as by wind direction, has been analysed, too. The European “Corine Land Cover 2000” classification of the study areas has been employed to deeply investigate the land use influence on both WSC and z₀ characteristics as a function of wind direction.Based on temperature and pressure surface measurements, the computation of site-specific mean air density as well as monthly variation has been also performed.Site-related 50-m wind resource has been assessed by means of wind roses and wind speed frequency distributions, as well as Weibull’s parameters. The potential turbine-converted wind energy yield has been also investigated, enabling to detect, for each site, the most suitable 50-m hub height turbine model regardless of its rated power. Furthermore, a number of comparisons have been made to assess the discrepancy in 50-m energy yield resulting if using data extrapolated from 10 m, both with 0.143 default and overall mean WSC value, instead of actually 50-m measured data.